Hi,

This is roughly a followup to:

  http://thread.gmane.org/gmane.lisp.guile.devel/6549/focus=6613

The attached patch adds an `scm_std_read ()' call, which is to read(2)
what `scm_std_select ()' is to select(2).  It changes `fport_fill_input'
to use it, which removes the call to select(2) that precedes each
read(2) call (!).

Using the same "I/O benchmark" as in my previous message, and compared
to Guile with the inlined `scm_getc' patch, it yields an additional 5%
speedup when reading by 4096-octet blocks, and a negligible improvement
when using smaller buffer sizes.

OK to apply?

Thanks,
Ludovic.